Global workplace safety standards are defining limits on the acoustic levels workers can be exposed to. These limits include short term levels and long term levels. For short periods, higher levels are allowed. For longer periods, from a fraction of an hour to a full work shift and up to a full day, the average sound pressure has a limit inversely proportional to the averaging time.
These national standards for acoustic limits are not limited to a single source such a communication device, but are the sum of all sources workers are exposed to over the course of the averaging time. Governmental and other agencies often provide information exposure limits for sound levels (see, FIGS. 1A-1B).